Downhole Wireless System for Tunneling Arrangements

ABSTRACT

A wireless data communication system within a tunneling tool used to form subterranean tunnels. The wireless data communication system is useful to provide real time data relating to tunneling and for controlling or adjusting the tunneling process.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the use of wireless communication systems to assist in creating downhole tunnels and passages.

2. Description of the Related Art

Efforts have been made to enhance production or create new production from existing wells by forming an opening through the casing of the wellbore and forming a tunnel through the formation beyond the casing. Tunneling arrangements which incorporate articulated joints largely prevent sensors from being effectively incorporated at or near the distal tunneling tool itself.

SUMMARY OF THE INVENTION

The invention provides tools and methods useful for creating tunnels within a formation surroundings a wellbore using a tunneling tool with one or more articulating joints. An exemplary jointed tunneling arrangement is described having a tunneling tool through which acid or fluids containing solids (i.e., sand) can be injected under high pressure through a distal nozzle to form a lateral tunnel. In other embodiments, a milling or directional drilling tool incorporates such articulating joints.

Wireless data communication is employed which permits sensors to be located proximate the nozzle of the tunneling tool and have sensor data transmitted across one or more articulating tool joints. In described embodiments, a wireless transmitter and wireless receiver are incorporated into the tunneling tool so as to transmit sensor data across at least one articulating joint of the tool. Sensors can detect one or more wellbore parameters, including angular orientation of the tunneling tool, pressure, temperature, location of the tunneling tool, minerology (gamma) and acidity (pH) of the acid entering the formation. Data is transmitted to a controller at surface via a data communication conduit, such as tubewire, or via other means. The wireless communication of the present invention allows for collection of better information since it permits sensors to be located at or near the distal end of the tool while data from the sensors is transmitted across an articulating joint. This data is useful for controlling and steering the tool.

BRIEF DESCRIPTION OF THE DRAWINGS

For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, wherein like reference numerals designate like or similar elements throughout the several figures of the drawings and wherein:

FIG. 1 is a side, cross-sectional view of an exemplary wellbore containing a tunneling tool in accordance with the present invention.

FIG. 2 is a side, cross-sectional view of an exemplary tunneling tool in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates an exemplary wellbore 10 which has been drilled through the earth 12 from the surface 14 to a hydrocarbon-bearing formation 16. The wellbore 10 is lined with metallic casing 18. In the depicted embodiment, it is desired to increase hydrocarbon production from the wellbore 10 by forming one or more tunnels within the formation 16 through which hydrocarbons can then enter the wellbore 10 through lateral window 20. In the arrangement shown in FIG. 1, a window 20 has previously been formed using a sidetracking mill, an abrasive perforator, or other means known in the art.

A tunneling arrangement, generally indicated at 22, is shown disposed within the wellbore 10 in FIG. 1. The tunneling arrangement 22 includes a running string 24, which is preferably formed of coiled tubing. A coiled tubing running string 24 is injected from surface by a coiled tubing injector (not shown) of a type known in the art. A flowbore 26 is defined along the length of the running string 24 to permit acid or fluid containing solids, such as sand, to be injected through the flowbore 26. A data communication conduit 28 is located within the flowbore 26 of the running string 24. Preferably, the data communications conduit 28 is tubewire. Telecoil® is coiled tubing which incorporates tubewire that can transmit power and data. Tubewire is available commercially from manufacturers such as Canada Tech Corporation of Calgary, Canada. In some embodiments, the tubewire incorporates an optical fiber for data transmission. Tubewire can transmit data along its length as well as electrical power.

A tunneling tool 30 is affixed to the distal end of the running string 24. The tunneling tool 30 is employed to form one or more tunnels within the formation 16 through window 20 in the casing 18. An exemplary tunneling tool 30 is depicted in greater detail in FIG. 2. It is noted that the particular tunneling tool 30 which is shown is an acid injection tunneling tool which uses acid, injected through the tool at high pressures, to create tunnels within the formation 16. It is noted that, in other embodiments, a tunneling tool may use sprays of fluid containing sand or other solids to form tunnels. In other embodiments, the tunneling tool 30 may comprise a rotary drilling or milling bit.

Generally, the tunneling tool 30 includes a main body portion 32 which secures to the running string 24. An intermediate body portion 34 is secured to the main body portion 32 by a first articulating joint 36. A lower body portion 38 is secured to the intermediate body portion 34 by a second articulating joint 40. The first and second articulating joints 36, 40 allow the body potions which they join to move angularly with respect to one another. It is noted that the lower body portion 38 and the main body portion 32 are separated from each other by at least one articulating joint which permits relative angular movement between the lower body portion 38 and the main body portion 32. The lower body portion 38 may be thought of as a first body portion and the main body portion 32 may be thought of as a second body portion which is separated from the first body portion by at least one articulating joint (i.e., 36, and/or 40) which permits angular movement between the first and second body portions. An axial fluid flowpath 42 is defined through the tunneling tool 30. Nozzle 44 is positioned at the distal end of the lower body portion 38 and is useful to direct sprays of acid into the formation 16 to form tunnels. Acid is communicated from the flowbore 26 of the running string 24 to the nozzle 44 via flowpath 42. The acid is flowed from surface 14 under the impetus of a fluid pump (not shown) at surface, of a type known in the art. The pumping pressure of the fluid pump can be adjusted (increased or decreased) as desired by an operator.

The first and second articulating joints 36, 40 allow the body portions that are affixed to them to bend and flex angularly relative to each other. In the depicted embodiment, there are two articulating joints 36, 40. It is noted, however, that the devices and methods of the present invention might also be applied to tools which incorporate only a single articulating joint or more than two articulating joints. It is noted that the use of multiple articulating joints is preferred since it allows three dimensional freedom of movement of the nozzle 44 with respect to the main body portion 32 during operation. Each of the articulating joints 36, 40 is preferably a pressure-operated knuckle joint.

As FIG. 1 shows, a controller 46 is located at surface 14 and is interconnected with the data communication conduit 28 so as to receive data therefrom. The data communication conduit 28 is also operably associated with a telemetry sub 48 within the main body portion 32 of the tunneling tool 30. The main body portion 32 also preferably includes an indexing tool 50 which can rotate the tunneling tool 30 angularly with respect to the running string 24. The controller 46 is preferably a programmable digital device, such as a computer, which can remotely control (i.e., from surface) the indexing tool 50 and thus the angular orientation of the tunneling tool 30.

Sensors 52 are incorporated into the lower body portion 38. Preferably, at least some of the sensors 52 are located at or near the distal end of the lower body portion 38 proximate the nozzle 44. The sensors 52 are configured to detect one or more of the wellbore parameters which include temperature, pressure, acceleration of the nozzle 44 and angular orientation of the nozzle 44, location of the tunneling tool 30, and minerology (gamma). In addition, the wellbore parameters sensed by the sensors 52 can include the acidity (pH) of the acid entering the formation 16 from the nozzle 44. The sensors 52 can transmit to surface 14 real-time data regarding tunnel mapping. Tunnel mapping data can include information relating to the tunnel orientation, length and formation properties (pressure, temperature and minerology). Based upon the tunnel orientation and length, the coiled tubing operator can decide if the tunnel forming should continue or if the tunneling tool 30 should be steered in a new direction by rotating the indexing tool 50. A wireless transmitter 54 is also incorporated into the lower body portion 38 and is operably associated with the sensors 52 to receive data from the sensors 52 and generate a wireless signal or signals representative of the data. Sensors can detect angular orientation, pressure, temperature or other downhole parameters.

A wireless receiver 56 is housed within the telemetry sub 48 and is operable to receive wireless signals generated by the wireless transmitter 54. The wireless data link between the transmitter 54 and the receiver 56 can be any form or protocol of wireless data communication that is effective to convey data across rotating or bending joints in a tool string. Wireless communication media is preferably radio wireless, but might also include optical, or sound-based wireless communications. Wireless telemetry is used to record and transmit, in real time, at least some of the parameters which include the location, speed, acceleration, and inclination of the lower body portion 38 or the volume and/or pH of the acid being injected into the formation 16.

Data sensed by the sensors 52 is preferably transmitted from the wireless receiver 56 to the controller 46 at surface via data communications conduit 28. Alternatively, the data might be transmitted to the controller 46 via fiber optic or other electrical wiring or even mud pulse telemetry.

Data received by the controller 46 from the sensors 52 is useful for controlling and/or steering the nozzle 44 of the tunneling tool 30. Data received by the controller 46 will indicate to an operator how a tunnel is developing (direction, length, angular orientation). In accordance with preferred methods, data relating to tunneling is used to control at least one aspect of operation of the tunneling tool 30. Controlling aspects of operation of the tunneling tool 30 include at least one of: altering the angle or direction of the tunneling tool, adjusting acid flow rate to the tunneling tool, and adjusting weight on bit. The weight on bit is typically maintained above a minimum value that guarantees that the coiled tubing doesn't buckle and can be changed from surface based on the real-time monitoring of such parameters as pumping rate, formation minerology/heterogeneity and tunnel shape/size. Depending on the real-time tunnel mapping, a coiled tubing operator could control/steer the tunneling tool 30 such that acid flowing out through the nozzle 44 will dissolve formation rock from a different angle, changing the orientation of the tunnel being formed. If the inclination of the tunnel/tunneling tool 30 is not as desired, the controller 46 could command the indexing tool 50 to rotate to correct the issue. The indexing tool 50, as well as the articulating joints 36, 40 are typically pressure-activated from surface and can be controlled by varying fluid pressure from surface 14. Alternatively, the indexing tool 50 and articulating joints 36, 40 could be electrically actuate via electrical power supplied from the surface 14. Based upon real time data showing the length of the tunnel being created, the acid pumping rate can be adjusted to increase or decrease the rate of tunnel formation.

The invention provides a tunneling arrangement which includes at least first and second body portions that are affixed by one or more articulated joints. A wireless transmitter 54 is incorporated into a first body portion (i.e., lower body portion 38), and a wireless receiver is incorporated into a second body portion (i.e., main body portion 32). There may be any number of intermediate portions, such as intermediate body portion 34, which are located between the first body portion and the second body portion.

Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow and any equivalents thereof. 

What is claimed is:
 1. A tunneling arrangement for creating a subterranean tunnel, the tunneling arrangement comprising: a first body portion which incorporates a tunneling tool; a second body portion that is separated from the first body portion by an articulating joint which permits angular movement between the first and second body portions; a wireless transmitter incorporated into the first body portion; and a wireless receiver incorporated into the second body portion, the wireless receiver configured to receive data from the wireless transmitter.
 2. A tunneling arrangement of claim 1 wherein the wireless transmitter transmits wireless data to the wireless receiver across the articulating joint.
 3. The tunneling arrangement of claim 1 further comprising a sensor associated with the tunneling tool to detect at least one wellbore parameter related to tunneling and provide data indicative of the at least one wellbore parameter to the wireless transmitter.
 4. The tunneling arrangement of claim 1 further comprising: a controller configured to receive data from the wireless receiver and to at least partially control operation of the tunneling tool; a data communications conduit interconnecting the wireless receiver with the controller.
 5. The tunneling arrangement of claim 4 wherein the data communications conduit comprises tubewire.
 6. The tunneling arrangement of claim 1 wherein the tunneling tool comprises an acid injection tunneling tool.
 7. The tunneling arrangement of claim 3 wherein the wellbore parameter relating to tunneling comprises at least one of angular orientation of the tunneling tool, pressure, temperature, location of the tunneling tool, minerology (gamma) and acidity (pH) of the acid entering the formation.
 8. A tunneling arrangement for creating a subterranean tunnel, the tunneling arrangement comprising: a first body portion which incorporates a tunneling tool; a second body portion that is separated from the first body portion by an articulating joint which permits angular movement between the first and second body portions; a sensor disposed upon the tunneling tool to detect at least one wellbore parameter related to tunneling; a wireless transmitter incorporated into the first body portion, the wireless transmitter receiving data from the sensor relating to tunneling; a wireless receiver incorporated into the second body portion, the wireless receiver configured to receive the data from the wireless transmitter; and a controller configured to receive the data from the wireless receiver and, in response, at least partially control operation of the tunneling tool.
 9. The tunneling arrangement of claim 8 wherein the wireless transmitter transmits the data wirelessly to the wireless receiver across the articulating joint.
 10. The tunneling arrangement of claim 8 wherein: the controller is located at a surface location; and a data communications conduit interconnects the wireless receiver with the controller.
 11. The tunneling arrangement of claim 10 wherein the data communications conduit comprises tubewire.
 12. The tunneling arrangement of claim 8 wherein the wellbore parameter relating to tunneling comprises at least one of angular orientation of the tunneling tool, pressure, temperature, location of the tunneling tool, minerology (gamma) and acidity (pH) of the acid entering the formation.
 13. A method of controlling a tunneling tool to form a subterranean tunnel within a formation, the method comprising the steps of: disposing a tunneling tool within a wellbore, the tunneling tool having first and second body portions which are separated from each other by an articulating joint which permits angular movement between the first and second body portions; and wirelessly communicating data relating to tunneling from the first body portion to the second body portion across the articulating joint.
 14. The method of claim 13 further comprising the steps of: communicating the data relating to tunneling to a controller; and adjusting at least one aspect of operation of the tunneling tool in response to the data.
 15. The method of claim 14 wherein the step of adjusting at least one aspect of operation of the tunneling tool comprises changing at least one of: altering the angle or direction of the tunneling tool, adjusting acid flow rate to the tunneling tool, and adjusting weight on bit.
 16. The method of claim 14 further comprising the step of sensing the data relating to tunneling with at least one sensor which is disposed upon the tunneling tool.
 17. The method of claim 16 wherein the data relating to tunneling is a wellbore parameter of the group consisting of: angular orientation of the tunneling tool, pressure, temperature, location of the tunneling tool, minerology (gamma) and acidity (pH) of the acid entering the formation. 